Hi, I thought I'd file two separate bug reports with details of test installations (with main-only images, and with firmware-enabled images), on two test machines (one with Radeon, one with Nvidia), but after having collected information from a single test installation, I fear this is going to be a waste of time for no real added value. Therefore, I'll just reply inline with my current gut feelings.
This is an overlong mail, apologies for that, but both topics are somewhat connected, so… Release team, you can search for @RT to jump at partial conclusions. Cyril Brulebois <k...@debian.org> (2021-06-14): > This is an umbrella bug report that I intend to use to track at least > two separate issues (that are really the two sides of the same coin): # main-only images > - Official installation images (main-only) might lead to a successful > installation but result in a black screen upon rebooting the > installed system. Some of these issues are due to free drivers > wanting or even requiring some firmware to work properly, on a > per-device basis. ## isenkram-based proof-of-concept I've investigated isenkram as a possible thing to document for end-users to try whenever they have firmware-related issues. Let me say upfront that this requires being able to log into the installed system: it relies on having the “missing firmware” messages in dmesg, and automates looking up the relevant firmware packages, enabling contrib/non-free, and installing the firmware packages that were detected as needed. A couple of comments: - When I first looked into it, I must say I wasn't exactly impressed by the state of the isenkram-autoinstall-firmware script in the isenkram-cli package (#989884); it was easy enough to fix the multiple issues in there to make it functional again in bullseye though. - The initial reaction to #989884 made me doubt whether we should be relying on this component, at least for a moment: While I understand the maintainer's point of view regarding what the package's main goals are, it felt like our d-i needs were handwaved away somehow. Practically though, the patches were merged in a timely manner, and as long as we can rely on that for the duration of a stable release, we might have a sufficiently good answer for people looking to complete the Debian installation. - The issues I fixed in isenkram-cli were around some fallback code path, and the AppStream maintainer suggested there might have been some issues in AppStream causing the primary code path to fail: https://bugs.debian.org/989884#24 The relevant update was accepted into testing since then, but I haven't had a chance to check that hypothesis. It would be great to know whether we actually have two working lookup implementation and not just the fallback one. (This could mean more reliability during a release cycle, in case one of them breaks — again.) ## unability to reproduce black screens with test hardware While the two test laptops (that were sent to me for debugging purposes) were picked to come with two possibly problematic video cards, I haven't been able to produce the black screen I was trying to get: the Radeon one manages to work with llvmpipe out of the box (switching to RENOIR once firmware is installed + reboot has happened), the Nvidia one has an Intel GPU anyway. I've tested the nomodeset kernel command line option though, which gets me a working graphical environment as well with different settings, and I *think* the system was using fallback, generic drivers (think VESA, FBDEV, and the like), but I couldn't 100% confirm this by checking X logs (which is slightly ironic for a former X maintainer but oh well). I also *think* using this option would help people dodge the black screen they can get with some other hardware, so that they can follow the isenkram-based procedure; I haven't been able to confirm that myself yet. It might make sense to have a call for help/feedback here, along those lines: “after installing Debian with a graphical environment, if you get a black screen, does passing `nomodeset` on the kernel command line help get the system boot to a graphical environment? [y/n]”. We might ask for more details like the actual hardware they're testing with, to see where the workaround is effective (and where it's needed). I don't view this call for help/feedback as a blocker for a d-i release, or for 11.0; we can always refine documentation if that hint is not sufficient. And hopefully, people assisting end users will suggest using firmware-enabled images anyway (read more about that below). ## proposed solution If others agree, I suggest we add the following somewhere in the installation guide (I don't think we should have a specific warning in the installer; or more specifically it would be way too late to have it be shown localized at this stage; more on that in the second part of my mail). Heavily summarized (to give readers of this bug report an idea, not for direct user consumption!!!): 1. Sometimes, bad luck, your system requires some firmware packages, which might not have been detected during the installation. Furthermore, they are usually in the contrib or non-free sections (insert big fat warning), and wouldn't be installed automatically. From an installed system, the following instructions would look for missing firmware files, find the relevant packages, and install them, automatically enabling contrib and/or non-free as required: sudo apt install isenkram-cli sudo isenkram-autoinstall-firmware Then reboot the system. [Whether we document other package managers, how to open a terminal emulator, etc. is left as an exercise for the documentation writers. Ditto for the practical consequences, meaning an extra sources.list file, which would be some implementation-specific details that could change over time. At the moment though, that'd be: /etc/apt/sources.list.d/isenkram-autoinstall-firmware.list; it also uses deb.debian.org — hardcoded] 2. Sometimes, bad luck, you might get a black screen when booting the installed system. Hopefully that can be worked around by adding the `nomodeset` option on the Linux kernel command line [maybe we already have some places where we document how to do that in GRUB]. If that trick works, you should be able to execute the instructions mentioned above from the system booted in a “failsafe mode”. @RT: I'd be happy to have some feedback from your regarding this approach; telling people to enable contrib/non-free so that they can install firmware packages is definitely *not* something I take lightly, but I'd be happy to have some kind of review there to see if that looks reasonable at all. I'm not sure there are many options these days anyway… Bonus point with this approach: we don't need to touch the installer, we can merge translations to the installation guide as they flow in, and the website should have an uptodate documentation as long as the debian-www sync works fine (I don't recall exactly how that works, I think we have various, per-release directories on the website; we might need to get the source package accepted in the relevant suite though, but we know how to deal with stable-proposed-updates, so…). ---------------------------------------------------------------------- # firmware-enabled images > - Unofficial installation images (shipping firmware from non-free) > might also lead to a successful installation but result in the same > kind of issue due to the way firmware detection is happening. ## easy, but ugly fix A fallback plan would be to just install all firmware packages. That would be *nasty*, would lead to some fun for at least one of them which requires accepting some EULA; from my IRC ramblings, those might be problematic and might need blacklisting or special handling: - firmware-ipw2x00 (EULA, IIRC; didn't recheck) - firmware-ivtv (EULA, IIRC; didn't recheck) - firmware-microbit-micropython* (conflicts with the doc package) - firmware-b43-installer (only a downloader) - firmware-b43legacy-installer (only a downloader) If we were to go the “(almost) all in” route, it might make sense to either blacklist (some of) those, or to whitelist the known-ok ones, which would require some monitoring of new additions over time (which dillon, behind d-i.debian.org, could help us with). @RT: This is my worst case scenario approach, letting us ship an installer (for firmware-related images) that have fewer chances of letting users get a black screen. ## more targeted approach: modalias information As a reminder, the missing firmware detection logic in the installer uses dmesg to detect specifically-formatted messages mentioning firmware files; this doesn't work for a variety of components, at least: - video drivers: we use fbdev and don't try to get all the fancy DRM things up and running → we cannot know radeon, nouveau, or whatever are going to require this or that firmware file in the installed system; - sound driver: firmware-sof-signed might be required to get sound up and running on some Intel boards. Ben suggested augmenting AppStream metadata (see DEP-11) of firmware-nonfree binaries with modalias information, so that it would be feasible to establish some hardware → firmware mapping. It's not been included in the archive yet, see MR#19 for src:firmware-nonfree: https://salsa.debian.org/kernel-team/firmware-nonfree/-/merge_requests/19 Specific snippets can be checked at: https://people.debian.org/~benh/firmware-metainfo/ I have verified that crossing those modalias entries with info extracted from udev would let us spot that this or that specific firmware package would be interesting (even if I don't think we can ever be sure how *required* a given firmware is), instead of installing them all. In particular, I have verified that a netboot-gtk build of the installer, booted under FBDEV as usual, does report the relevant AMD or Nvidia card via `udevadm info -e`, and that it makes it possible to decide installing firmware-amd-graphics (AMD) or firmware-misc-nonfree (Nvidia). This doesn't help us (yet) regarding Intel SOF, since that package is (ultimately) built from src:firmware-sof, which doesn't have this logic yet. But I don't think we should delay the release for that (it could be listed in errata, and/or fixed in 11.1, whenever the package is ready), and if the machine at least boots fine, including the graphics stack, the isenkram trick above should let users install the remaining firmware packages on their own. There might be other “widely spread” firmware that might benefit from the same logic, but I won't be spending too much time thinking about this right now; such patches can come later, and those updated package firmwares should be pickled up automatically afterwards. Regarding the implementation, my current approach would be: - have firmware-nonfree's MR merged and uploaded; - make sure the relevant information bubbles up to the dep11/Components files (YAML format, even if the excerpts above were XML); - have debian-cd extract the relevant firmware package←→modalias mapping from YAML into one or N flat files to be consumed by d-i, for firmware-enabled images primarily (or exclusively); - patch d-i to consume that or those files to queue up as many firmware packages as required. Note: it's likely that at least some firmware packages are going to be installed rather early in the installation process; network drivers (wired and/or wireless ones) are likely going to be probed early, and have generated the relevant messages in dmesg. I have still to familiarize myself with the whole (existing) “automatic installation of firmware packages when running on a firmware-enabled image” logic though, to see where the patches would be best suited. Still a gut feeling at this stage: a finish-install script, running before the final update-initramfs one, might be the best place to do that final check; it would build the list of interesting firmware packages, and either skip those which are installed already, and install the others; or just apt install the whole list, and let apt be a no-op for all those already installed. @RT: This would be my preferred approach, and based on cdbuilder coming back up, plus my recent verifications in a d-i context, I think this should be manageable in time for the announced release date. Ideally we would be able to release an RC3 a week from now, letting us fix any boo-boo in time before mid-August. # final thought Circling back to the main-only images, having that hardware→firmware lookup would let us have a chance to mention that “this and that and that firmware package might be needed on your system”, adding a pointer to the “isenkram procedure” of the installation guide. If that'd be desired, the relevant mapping file would need to end up not only in firmware-enabled images, and we would need new strings, new translations, and that's almost certainly only achievable during the next release cycle. In any cases, I'm happy to start with something specific to the firmware-enabled images anyway, so that the possible fallouts are contained within a rather known and well-defined area. We should have enough time to implement that for 11.0, but we don't have *plenty*. Thanks for your attention! I've had plenty on my mind, and some braindump was in order. Sorry it's been *that* long a read. Cheers, -- Cyril Brulebois (k...@debian.org) <https://debamax.com/> D-I release manager -- Release team member -- Freelance Consultant
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